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Ummm, that *might* work. Really, your best bet, if you want what you're trying to stick to hold and be durable, is underwater epoxy....lots of fish stores carry it and it would be the most dependable for you.
I would stay away from using gorilla glue. It is a great glue but the one marine application I have used it in (mysid culture) did not turn out so well. The mysid died shortly after being in the tank. The glue had dried thoroughly, and there may be other factors, but no chances should be taken when dealing with cephalopods.